The Pharaoh’s Serpent

Mercury(II) thiocyanate (Hg(SCN)2) is a chemical compound. It is a white powder that produces a large, winding “snake” when ignited in an effect known as the Pharaoh’s Serpent. Mercury thiocyanate was first discovered by Wöhler  in 1821, soon after the first synthesis of mercury thiocyanate he commented that: "winding out from itself at the same time worm-like processes, to many times its former bulk, a very light material the colour of Graphite." The effect is created when the compound of mercury & thiocyanate, is in the presence of a strong enough heat source. A rapid Exothermic reaction ensues. It produces a large mass of coiling serpent-like, solids. An inconspicuous flame accompanies the combustion. The resulting solid has a small range of colours, usually being tan or light grey, the inside however is much darker than the outside.

 The compound was available to the public in Germany, but was eventually banned when the toxic properties of the product were discovered through the death of several children who mistakenly ate the resulting solid.

Mercury thiocyanate, is still used however, and is quite a spectacle on the occasion someone with the materials and know-how can ignite The Pharaoh’s Serpent.

See the video bellow for an example: